<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>title</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
 
        html, body {
            height: 100%;
        }
 
        body {
            border: 1px solid #000;
            /*box-sizing可以取消因为添加border而出现的滚动条*/
            box-sizing: border-box;
            background-color: skyblue;
        }
    </style>
</head>
<body>
 
</body>
</html>